Priming valve to induce appropriate pressure and flow profile and improve sensor readiness

ABSTRACT

A priming valve includes a fluid flow path, a fluid inlet configured to couple to a fluid outlet of a fluid channel including at least one sensor configured to characterize at least one attribute of a fluid, a fluid outlet, a valve seat, and a connector. The connector engages the valve seat to prevent fluid flow via the fluid flow path. The connector is configured to move relative to the valve seat in response to a threshold pressure within the fluid flow path to allow the fluid to flow via the fluid flow path. A flow sensor sub-assembly for sensing flow of a fluidic medicament may include a priming valve and at least one sensor of a fluid port configured to characterize at least one attribute of a fluid within an administrable fluid source. A method for readying a fluid sensor may use a priming valve.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 16/007,245, entitled “Priming Valve to Induce AppropriatePressure and Flow Profile and Improve Sensor Readiness”, filed Jun. 13,2018, which claims priority to U.S. Provisional Application Ser. No.62/521,726, entitled “Priming Valve to Induce Appropriate Pressure andFlow Profile and Improve Sensor Readiness”, filed Jun. 19, 2017, theentire disclosures of each of which are hereby incorporated byreference.

BACKGROUND OF THE INVENTION 1. Field of the Disclosure

The present disclosure relates generally to a flow sensor system. Moreparticularly, the present disclosure relates to a flow sensor system anda method of readying a flow sensor of the flow sensor system forcharacterizing at least one attribute of a fluid to be detected by theflow sensor.

2. Description of the Related Art

There is a need to improve volume accuracy in a bolus delivery using amedical device. It would be advantageous to provide a flow sensor systemhaving a flow sensor with improved flow measurement characteristics.

SUMMARY OF THE INVENTION

The present disclosure provides a system for sensing a flow of a fluidicmedicament. The system includes an intelligent injection port which mayattach to an injection site (such as a “Y Site” or a stop cock) formanually administered IV injections. The system includes two mainsub-assemblies: a single-use flow sensor and a reusable base unit, whichfit together prior to use. The single-use flow sensor includes a flowtube sub-assembly.

In accordance with an example of the present invention, priming valvefor a fluid sensor associated with a medical device may include a valvecomprising a fluid flow path, a fluid inlet at a first end of the fluidflow path configured to couple to a fluid outlet of a fluid channelincluding at least one sensor configured to characterize at least oneattribute of a fluid, a fluid outlet at a second end of the fluid flowpath, a valve seat, and a connector that engages the valve seat toprevent fluid flow between the fluid inlet and the fluid outlet via thefluid flow path, wherein the connector is configured to move relative tothe valve seat in response to a threshold pressure within the fluid flowpath to allow the fluid to flow between the fluid inlet and the fluidoutlet of the valve via the fluid flow path.

According to further examples, the threshold pressure is 5-50 psi.

According to further examples, the connector comprises a sidewallextending between an inlet end and an outlet end of the connector,wherein the valve seat comprises a sidewall extending between an inletend and an outlet end of the valve seat, and wherein at least a portionof the valve seat extends within the connector such that an innersurface of the sidewall of the connector faces an outer surface of thesidewall of the valve seat.

According to further examples, the outer surface of the sidewall of thevalve seat comprises a lip portion that extends radially outward fromthe sidewall of the valve seat, and wherein the inner surface of thesidewall of the connector is slidingly and sealingly engaged with thelip portion of the valve seat.

According to further examples, the lip portion of the valve seatcomprises one of a molded lip seal and an o-ring.

According to further examples, an inner surface of the sidewall of thevalve seat defines a first portion of the fluid flow path extending fromthe fluid inlet of the valve to at least one opening in the sidewall ofthe valve seat, wherein the at least one opening in the sidewall of thevalve seat is located in a direction toward the fluid outlet of thevalve with respect to the lip portion of the valve seat, and wherein theinner surface of the sidewall of the connector and the outer surface ofthe sidewall of the valve seat define a second portion of the fluid flowpath extending from the opening toward the fluid outlet of the valve.

According to further examples, the connector is configured to moveaxially away from the inlet end of the valve seat in a direction towardthe outlet end of the valve seat in response to the threshold pressurewithin the fluid flow path to allow the fluid to flow between the fluidinlet and the fluid outlet of the valve.

According to further examples, a portion of the sidewall of theconnector extends radially inward at the inlet end of the connector.

According to further examples, the outer surface of the sidewall of thevalve seat comprises at least one abutment surface that extends radiallyoutward from the sidewall of the valve seat, wherein the at least oneabutment surface is configured to engage the portion of the sidewall ofthe connector that extends radially inward to inhibit further movementof the connector axially away from the inlet end of the valve seat inthe direction toward the outlet end of the valve seat.

According to further examples, the inner surface of the sidewall of theconnector comprises at least one detent extending radially inward fromthe sidewall.

According to further examples, the outer surface of the sidewall of thevalve seat comprises at least one abutment surface extending radiallyoutward from the sidewall, wherein the at least one abutment surface isconfigured to engage the at least one detent to inhibit further movementof the connector axially away from the inlet end of the valve seat inthe direction toward the outlet end of the valve seat.

According to further examples, the outer surface of the sidewall of thevalve seat comprises at least one additional abutment surface extendingradially outward from the sidewall, wherein the at least one additionalabutment surface is located in a direction toward the inlet end of thevalve seat with respect to the at least one abutment surface, andwherein the at least one additional abutment surface is configured toengage the at least one detent to inhibit movement of the connectoraxially toward the inlet end of the valve seat in a direction away fromthe outlet end of the valve seat.

According to further examples, the valve further comprises an additionalfluid flow path between the fluid inlet and the fluid outlet of thevalve.

According to further examples, the inner surface of the sidewall of theconnector comprises an angled surface that extends radially inwardtoward the outlet end of the connector, wherein the outer surface of thesidewall of the valve seat comprises a valve seat surface, and whereinthe angled surface of the connector engages the valve seat surface ofthe valve seat to prevent fluid flow between the fluid inlet and thefluid outlet via the fluid flow path.

According to further examples, the valve comprises a connection at thefluid outlet at the second end of the fluid flow path configured toconnect to an inlet configured to deliver the fluid from theadministrable fluid source to a fluid pathway that provides the fluid tosaid medical device.

In accordance with an example of the present invention, a flow sensorsub-assembly for sensing flow of a fluidic medicament may include atleast one sensor of a fluid port configured to characterize at least oneattribute of a fluid within an administrable fluid source, the fluidport comprising: a fluid channel, a fluid inlet at a first end of thefluid channel configured to couple to an outlet of an administrablefluid source, and a fluid outlet at a second end of the fluid channel;and a priming valve attached to the fluid outlet at the second end ofthe fluid channel, wherein the priming valve is configured to preventfluid flow from the fluid outlet at the second end of the fluid channelwhen closed, and wherein the priming valve is configured to open toallow the flow of the fluid from the fluid outlet at the second end ofthe fluid channel in response a threshold pressure within the fluidchannel.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of thisdisclosure, and the manner of attaining them, will become more apparentand the disclosure itself will be better understood by reference to thefollowing descriptions of examples of the disclosure taken inconjunction with the accompanying drawings, wherein:

FIG. 1 is a distally-directed perspective view of a flow sensor systemin accordance with one example of the present invention.

FIG. 2 is a distally-directed perspective view of a flow sensor systemin accordance with one example of the present invention.

FIG. 3 is an exploded, perspective view of a flow sensor of a flowsensor system in accordance with an example of the present invention.

FIG. 4 is a perspective view of a flow sensor of a flow sensor system inaccordance with an example of the present invention.

FIG. 5 is a graph showing signal level of a flow sensor of a flow sensorsystem as a function of time according to one example case.

FIG. 6 is a graph showing signal level of a flow sensor of a flow sensorsystem as a function of time according to another example case.

FIG. 7 is an exploded perspective view of a flow sensor system inaccordance with one example of the present invention.

FIG. 8 is a schematic view of a priming valve in accordance with oneexample of the present invention.

FIG. 9 is a schematic view of a priming valve in accordance with oneexample of the present invention.

FIG. 10 is an exploded perspective view of a priming valve in accordancewith one example of the present invention.

FIG. 11 is a schematic view of a priming valve in accordance with oneexample of the present invention.

FIG. 12 is a schematic view of a priming valve in accordance with oneexample of the present invention.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate exemplary examples of the disclosure, and suchexemplifications are not to be construed as limiting the scope of thedisclosure in any manner.

DETAILED DESCRIPTION

The following description is provided to enable those skilled in the artto make and use the described examples contemplated for carrying out theinvention. Various modifications, equivalents, variations, andalternatives, however, will remain readily apparent to those skilled inthe art. Any and all such modifications, variations, equivalents, andalternatives are intended to fall within the spirit and scope of thepresent invention.

For purposes of the description hereinafter, the terms “upper”, “lower”,“right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, “lateral”,“longitudinal”, and derivatives thereof shall relate to the invention asit is oriented in the drawing figures. However, it is to be understoodthat the invention may assume various alternative variations, exceptwhere expressly specified to the contrary.

As used in the specification and the claims, the singular form of “a”,“an”, and “the” include plural referents unless the context clearlydictates otherwise.

As used herein, “proximal” shall refer to a part or direction locatedaway or furthest from a patient (upstream), while distal shall refer toa part or direction towards or located nearest to a patient(downstream). Also, a drug substance is used herein in an illustrative,non-limiting manner to refer to any substance injectable into the bodyof a patient for any purpose. Reference to a patient may be to anybeing, human or animal. Reference to a clinician may be to any person orthing giving treatment, e.g., a nurse, doctor, machine intelligence,caregiver, or even self-treatment.

As used herein, the phrase “inherently hydrophobic” refers to a surfacethat naturally excludes water molecules rather than by a process ofdrying, such as drying by hot air.

Unless otherwise indicated, all ranges or ratios disclosed herein are tobe understood to encompass any and all subranges or subratios subsumedtherein. For example, a stated range or ratio of “1 to 10” should beconsidered to include any and all subranges between (and inclusive of)the minimum value of 1 and the maximum value of 10; that is, allsubranges or subratios beginning with a minimum value of 1 or more andending with a maximum value of 10 or less, such as but not limited to, 1to 6.1, 3.5 to 7.8, and 5.5 to 10.

Unless otherwise indicated, all numbers expressing quantities used inthe specification and/or claims are to be understood as modified in allinstances by the term “about.”

Flow Sensor System

FIGS. 1-4 illustrate an exemplary configuration of a flow sensor system200 of the present disclosure. Referring to FIGS. 1-4 , a flow sensorsystem 200 of the present disclosure includes two main assemblies whichfit together prior to use: a flow sensor 210 and a base 220. In oneexample, the flow sensor 210 can be a single-use flow sensor which isengageable with a reusable base 220. The flow sensor system 200 is anintelligent injection port. The flow sensor system 200 is attachable toan injection site (“Y Site” or stop cock, for example) for manuallyadministered IV injections.

The flow sensor system 200 of the present disclosure can reducemedication error at bedside during bolus delivery. The flow sensorsystem 200 of the present disclosure can also provide a record of andelectronically measure bolus delivery, which allows monitoring bolusdelivery and automatic documentation of bolus delivery as part of apatient's health record. The flow sensor system 200 of the presentdisclosure can also provide alerts when bolus delivery inconsistent witha patient's medical record is about to occur.

Referring to FIGS. 1-4 , in one example, the base 220 is a non-sterile,reusable device that houses a battery, a scanner (either optical,mechanical, inductive, capacitive, proximity, or RFID), electronics, anda wireless transmitter. In some examples, the base 220 is batterypowered and rechargeable. In some examples, each base 220 has a uniqueserial number imprinted on a surface of the base 220 or embedded thereinthat may be transmitted to a data system before use. The data system canbe a local computer or tablet “computer”, a cellular phone, anothermedical device, or a Hospital Data System.

Referring to FIGS. 1-4 , in one example, the base 220 is removablyconnectable to the flow sensor 210 and includes at least one deflectablewing tab 280 defining an opening for receiving at least a portion of theflow sensor 210 therein and for securing the flow sensor 210 within aportion of the base 220 prior to use. In one example, a pair of wingtabs 280 secure the flow sensor 210 within the base 220. The wing tabs280 may be flexible to the extent that they may be outwardly deflectedto allow for passage of the flow sensor 210 thereover. In one example,the flow sensor 210 is a pre-sterilized disposable device having aninjection port 130 and a distal tubing connection, such as a Luer tip109, which may be optionally covered by a Luer cap 108.

With reference to FIG. 3 , the flow sensor 210 may include a flow tubesub-assembly 10 consisting of a flow tube 100 having an outlet end 101and an inlet end 102. The outlet end 101 may be provided in fluidcommunication with an outlet tubing 110 having an outlet connection 105including a Luer tip 109 which may be optionally covered by a flowrestrictor, as described herein. In a preferred example, the outletconnection 105 is a plastic connector with a Luer tip 109, however, anysuitable method to inject the medicament into a patient is envisaged tobe within an aspect of an example of the invention. For example, it maybe desirable to replace the outlet connection 105 and tubing 110 with aneedle for direct injection/infusion into a patient.

The inlet end 102 may be coupled to the reservoir of a medication pen orinfusion reservoir. The inlet end 102 of the flow tube 100 may beprovided in fluid communication with an injection port 130, and mayoptionally include a connection such as a threaded Luer lock 131 whichis engageable with a source of a fluid to be injected. A pierceableseptum (not shown) may be provided with the injection port 130 formaintaining sterility prior to use. In one example, the flow tube 100 iscomprised of a medical grade stainless steel and is approximately 50 mmlong with a 1.0 mm inner diameter and a 1.6 mm outer diameter.

In one example, the flow sensor system 200 supports injections using anyLuer-lock type syringe or liquid medicament container. Additionally, theflow sensor system 200 is designed to work with encoded syringes thathave a special barcode identifier on the Luer collar of the syringe,called “encoding”. Preferably, encoded syringes includecommercially-available drugs in prefilled syringes with a specialbarcode that stores information about the medication contained withinthe syringe. Encoded syringes are ready-to-use, passive, and disposable.The encoding syringes store the drug name and concentration containedwithin the syringe. Additional characteristics such as drug source,container size, drug manufacturer source, drug category color, amongothers, may also be included. When an encoded syringe is attached to theinjection port 130 of the flow sensor 210, this barcode information isread by a scanner in the base 220 and wirelessly transmitted by the flowsensor system 200 to the data system. Preferably, the 2-D barcodes willbe added to syringes during the filling process. The flow sensor system200 also accommodates syringes not having encoding.

The present disclosure provides a flow sensor sub-assembly for sensingflow of a fluidic medicament. The flow sensor 210 also includes a firstpiezo element or an upstream transducer 150 and a second piezo elementor a downstream transducer 151. The first piezo element 150 may beprovided with an inlet fitting 180, as shown in FIG. 3 , for couplingwith the injection port 130. Similarly, the second piezo element 151 maybe provided with an outlet fitting 190, for coupling with the outlettubing 110. The first and second piezo elements 150 and 151 areconfigured to transmit an ultrasonic signal therebetween indicative of aflow of the fluidic medicament in the flow tube 100. In an example, thefirst piezo element 150 and the second piezo element 151 are annular inshape and encircle the flow tube 100 at each respective mounting point.

The flow sensor 210 includes a first spring contact 750 a and a secondspring contact 750 b. In one example, the spring contacts 750 a, 750 bare secured to a base 700 that has a circuit for conducting anelectrical signal to and from the spring contacts 750 a, 750 b to amicroprocessor. The first spring contact 750 a is in electricalcommunication with a first piezo element 150 and the second springcontact 750 b is in electrical communication with a second piezo element151. The first spring contact 750 a has a first contact force againstthe first piezo element 150 and the second spring contact 750 b has asecond contact force against the second piezo element 151. The firstcontact force may be equivalent to the second contact force. The firstand second piezo elements 150, 151 vibrate due to fluid flow through theflow tube 100 of the flow sensor 210. Vibration of the first and secondpiezo elements 150, 151 creates an ultrasonic signal which can bedetected and communicated electronically to the microprocessor. Themicroprocessor is configured to correlate the ultrasonic signal to afluid flow rate through the flow tube 100 and provide a fluid flow rateoutput to the user.

Method of Readying a Flow Sensor

Referring to FIGS. 1-2 , use of a flow sensor system 200 of the presentdisclosure will now be described. In one example, as the drug isinjected, the flow sensor system 200 measures the volume dosedultrasonically. In order to improve transmission of ultrasonic signalsin the flow sensor 210, the present disclosure proposes various examplesof increasing a fluid pressure in the flow sensor 210.

During manufacture, flow sensor 210 may be calibrated on a calibrationbench. For example, a fluid, such as water, is flowed through the flowsensor 210 to calibrate the ultrasonic signal transmission between thefirst and second piezo elements 150 and 151. Prior to packaging the flowsensor 210 for shipping, the flow sensor 210 may be dried, such as usinghot air, to eliminate any residual fluid that may remain in the flowsensor 210. Without intending to be bound by theory, hot air drying ofthe fluid path surfaces of the flow sensor 210 contributes to makingthese fluid path surfaces exhibit their inherently hydrophobiccharacteristics. In this manner, when the flow sensor 210 is readied foruse by priming the flow sensor 210 with a priming fluid, the interiorfluid path surface of the flow sensor 210 may not be fully wetted withthe priming fluid. Because the flow sensor 210 is configured to generateultrasonic signals corresponding to a flow rate of the fluid throughcontact with the internal flow path of the flow sensor 210, theinherently hydrophobic characteristics of the interior surface of thefluid path contribute to a decrease in the ability of the flow sensor210 to transmit ultrasonic waves. It has been found that wetting theinternal surfaces of the flow path through the flow sensor 210, such asby increasing a pressure or maintaining a pressure within the flow path,increases the ultrasonic signal transmission capability of the flowsensor 210.

With reference to FIG. 1 , a first method of readying the flow sensor210 will now be described. In this example, the flow sensor system 200is prepared for use by attaching the injection port 130 of the flowsensor system 200 to an administrable fluid source, such as a syringe900 containing a fluid. In some examples, the syringe 900 may contain apriming fluid, such as saline. Prior to connecting the syringe 900, theinjection port 130 is desirably cleaned by swabbing the hub according tonormal hospital procedure. The syringe 900 can be attached to theinjection port 130 by rotating the syringe 900 about its longitudinalaxis until the syringe 900 stops, i.e., a secure connection between thesyringe 900 and the injection port 130 is made. The syringe 900 has aplunger 920 for delivering the priming fluid from an interior of thesyringe 900 when the plunger 920 is pushed in a distal direction.

The outlet connection 105 is capped with a flow restrictor, such as acap 910. In some examples, the cap 910 is configured to interface withthe Luer tip 109 of the outlet connection 105. The cap 910 can beattached to the Luer tip 109 by rotating the cap 910 about itslongitudinal axis until the cap 910 stops, i.e., a secure connectionbetween the cap 910 and the Luer tip 109 is made. Once connected to theLuer tip 109, the cap 910 blocks fluid flow from the outlet connection105.

Next, the plunger 920 of the syringe 900 is pushed in the distaldirection to deliver fluid from the syringe 900. Because the cap 910prevents fluid from flowing out of the outlet connection 105, thepriming fluid from the syringe 900 builds fluid pressure within the flowsensor 210. In some examples, the increased fluid pressure of 5-50 psiwithin the flow sensor 210 can be maintained for a predetermined periodof time. For example, the predetermined period of time may beapproximately 1-60 seconds.

While the flow sensor 210 is pressurized by the fluid from the syringe900, at least one first signal is generated by the flow sensor 210 tocharacterize at least one attribute of fluid. In various examples, theat least one attribute may be fluid flow rate and/or fluid pressure. Themanual increase of fluid pressure within the flow sensor 210, whilekeeping the outlet connection 105 capped, helps eliminate any airbetween the interior surface of the flow path of the flow sensor 210 andthe fluid. In this manner, the interior surface of the flow path of theflow sensor 210 is fully wetted to allow for an increased ultrasonicsignal transmission of the flow sensor 210.

Next, the pressure on the plunger 920 of the syringe 900 can bereleased, and the cap 910 is removed from the Luer tip 109. The outletconnection 105 is attached to an inlet of a fluid pathway (not shown)configured for delivering fluid from an administrable fluid source, suchas the syringe 900, to a patient. In some examples, the fluid pathwaymay be a catheter configured for connecting to a patient. Prior toconnecting the fluid pathway to the patient, fluid from the syringe 900is first expelled from the fluid pathway, such as during the priming ofthe fluid pathway. As the fluid is delivered from the syringe 900, thefluid flows through the flow sensor 210 and out of the fluid pathway. Insome examples, 2-7 ml of fluid may be delivered from the syringe 900through the fluid pathway. The flow sensor 210 may generate at least onesecond signal of the same type as the first signal in order tocharacterize at least one attribute of the fluid. For example, thesecond signal may characterize the pressure and/or flow rate of fluidthrough the flow sensor 210. In some examples, the second signal may beincreased (i.e., have higher strength) than the first signal due to theinternal surfaces of the flow path of the flow sensor 210 being fullywetted. For example, the second signal may be increased over the firstsignal by 120%, 160%, or 180%, inclusive of the values therebetween. Theflow sensor 210 is now primed and ready for use in a fluid deliveryprocedure.

In various examples, the flow sensor 210 may be in communication with acontroller 930. The controller 930 may be configured for receivinginformation from the flow sensor 210, such as receiving the at least onefirst signal and the at least one second signal. The controller 930 maybe configured to determine that the at least one attribute of the fluidbased on the received data from the at least one first signal and the atleast one second signal matches at least one condition specified by atleast one rule. For example, the controller 930 may be configured foridentifying a type of fluid flowing through the flow sensor 210 based ona flow rate of the fluid through the flow sensor 210 for a given fluidpressure at a given fluid temperature. Without intended to be bound bytheory, each fluid, such as a fluid medicament, has a unique ultrasonicsignature as the fluid flows through the flow sensor 210. The ultrasonicsignature may be a function of fluid pressure, temperature, and materialcomposition of the fluid.

In various examples, the controller 930 may generate at least oneoperation modification signal in response to the characterized at leastone attribute matching at least one condition specified by at least onerule. For example, the controller 930 can execute a flow algorithm basedon data representing characteristics or attributes of the fluid flowreceived from the piezo elements 150, 151. In some examples, the syringe900 may have indicia that, when read by a reading device of the flowsensor system 200 that is in operative communication with the controller930, causes the controller 930 to initiate a predetermined operatingcycle. In some examples, the indicia may be a 2D or 3D barcode, QR code,or any other indicia capable of storing information that, when read by areading device of the flow sensor system 200, is configured to beinterpreted as a set of instructions to be performed by the controller930. For example, the indicia, when read by the reading device, cancause the controller 930 to initiate a priming cycle for priming theflow sensor 210. In some examples, the priming cycle may comprisegenerating at least one signal, such as a first signal and a secondsignal discussed herein.

The controller 930 may transmit, by a transmitter (not shown) theoperation modification signal to at least one device. In someembodiments, if a fluid type is determined to be a different type than adesired fluid type, or if a flow rate is determined to be a differentflow rate than a desired flow rate, the controller 930 can transmit anoperation modification signal to a display and/or a data processingmodule that causes the module to display an alarm or alert or causes themodule to transmit a signal back to the system 200 that stops the fluidflow. The controller 930 can further control the wireless transmitter totransmit injection data representing a type of medication, a dose of amedication, and/or a time of a dose of a medication to the displayand/or data processing module. In some embodiments, the controller 930can automatically transmit the data to the module in response to anautomated injection.

With reference to FIG. 5 , a graph depicting a percentage of signalstrength of five flow sensors 210 as a function of time is shown inaccordance with one example. Each flow sensor 210 was initiallycalibrated using a standard calibration routine. The signal readingsfrom each of the flow sensors 210 after calibration are shown as point Aon the graph. The flow sensors 210 were then dried with hot air andflushed with a priming fluid without being pressurized. Ultrasonicsignal transmission readings were then recorded, shown as point B on thegraph. From the graph in FIG. 5 , it can be readily observed that signalstrength drops for each of the flow sensors 210 after the flow sensors210 have been dried with hot air. In order to increase the signal level,each flow sensor 210 was capped with a cap 910 and pressurized with apriming fluid, such as saline, for 60 seconds. After the expiration ofthe pressurization period, another signal reading was taken. Point C inFIG. 5 illustrates that the signal level increases from Point B afterthe flow sensors 210 have been pressurized with a priming fluid.

With reference to FIG. 2 , instead of capping the outlet connection 105with a cap 910, such as described herein with reference to FIG. 1 , theoutlet connection 105 may be connected to a vented flow restrictor, suchas a vented cap 940. In some examples, the vented cap 940 may be aneedle having an inner diameter sufficiently small to be capable ofgenerating back pressure in the flow sensor 210 when fluid is deliveredfrom the syringe 900. For example, the vented cap 940 may be a needlehaving an outlet of approximately 30 G (0.16 mm ID). In other examples,the vented cap 940 may have an inner diameter of 0.1-0.2 mm. The primingfluid delivered from the syringe 900 builds back pressure within theflow sensor 210. In some examples, the increased fluid pressure of 5-50psi within the flow sensor 210 can be maintained for a predeterminedperiod of time. For example, the predetermined period of time may beapproximately 1-60 seconds.

While the flow sensor 210 is pressurized by the fluid from the syringe900, at least one first signal is generated by the flow sensor 210 tocharacterize at least one attribute of fluid. In various examples, theat least one attribute may be fluid flow rate and/or fluid pressure. Themanual increase of fluid pressure within the flow sensor 210, whilekeeping the outlet connection 105 capped, helps eliminate any airbetween the interior surface of the flow path of the flow sensor 210 andthe fluid. In this manner, the interior surface of the flow path of theflow sensor 210 is fully wetted to allow for an increased ultrasonicsignal transmission of the flow sensor 210.

Next, the pressure on the plunger 920 of the syringe 900 can bereleased, and the vented cap 940 is removed from the Luer tip 109. Theoutlet connection 105 is attached to an inlet of a fluid pathway (notshown) configured for delivering fluid from an administrable fluidsource, such as the syringe 900, to a patient. In some examples, thefluid pathway may be a catheter configured for connecting to a patient.Prior to connecting the fluid pathway to the patient, fluid from thesyringe 900 is first expelled from the fluid pathway, such as during thepriming of the fluid pathway. As the fluid is delivered from the syringe900, the fluid flows through the flow sensor 210 and out of the fluidpathway. In some examples, 2-7 ml of fluid may be delivered from thesyringe 900 through the fluid pathway. The flow sensor 210 may generateat least one second signal of the same type as the first signal in orderto characterize at least one attribute of the fluid. For example, thesecond signal may characterize the pressure and/or flow rate of fluidthrough the flow sensor 210. In some examples, the second signal may beincreased (i.e., have higher strength) than the first signal due to theinternal surfaces of the flow path of the flow sensor 210 being fullywetted. For example, the second signal may be increased over the firstsignal by 120%, 160%, or 180%, inclusive of the values therebetween. Theflow sensor 210 is now primed and ready for use in a fluid deliveryprocedure.

With reference to FIG. 6 , a graph depicting signal level of three flowsensors 210 (labeled 1, 2, 3) as a function of time is shown inaccordance with another example. Each flow sensor 210 was provided witha vented cap 940 having a 30 G needle. A signal count was recorded(Point D) during a delivery of 2 ml of fluid from the syringe 900. Thevented cap 940 was then removed from each flow sensor 210 and a signalcount illustrative of a pressure drop was recorded (Point E). From thegraph in FIG. 6 , it can be readily observed that signal strength dropsfor each of the flow sensors 210 after the vented cap 940 is removedfrom the flow sensors 210. After removing the vented cap 940, 7 ml offluid was delivered from the syringe 900 through each flow sensor 210.During this step, signal count increased and stabilized at a high value(Point F). A signal level of a fourth flow sensor 210 (labeled 4 in FIG.6 ), which has been primed without using the vented cap 940, is shown asa comparative example. The signal strength of the fourth flow sensor 210is significantly lower than a signal strength of flow sensors 210 thatwere readied using the vented cap 940 in a manner described herein withreference to FIG. 2 .

Flow Sensor System Relief Valve

With reference to FIG. 7 , instead of capping the outlet connection 105with a cap 910, such as described herein with reference to FIG. 1 , or avented flow restrictor, such as a vented cap 940 described herein withreference to FIG. 2 , the outlet connection 105 may be connected to apriming valve 950 as shown in FIG. 7 . In some examples, the primingvalve 950 is configured to interface with the Luer tip 109 of the outletconnection 105. The priming valve 950 can be attached to the Luer tip109 by rotating the priming valve 950 about its longitudinal axis untilthe priming valve 950 stops, i.e., a secure connection between thepriming valve 950 and the Luer tip 109 is made.

Once connected to the Luer tip 109, the priming valve 950, when closed,prevents fluid flow from the outlet connection 105 as described in moredetail herein. The priming valve 950 is configured to open to allowfluid flow from the outlet connection 105 in response a thresholdpressure within the flow sensor 210. For example, the outlet tubing 110includes a fluid channel between a fluid inlet in fluid communicationwith the outlet end 101 of the flow tube 100 of flow sensor sub-assembly10 and the outlet connection 105, and the priming valve 950 attached tothe outlet connection 105 can be configured to open to allow the flow ofthe fluid from the outlet connection 105 in response a thresholdpressure within the fluid channel of the outlet tubing 110.

Referring now to FIGS. 8 and 9 , the priming valve 950 includes a fluidflow path 952, a fluid inlet 954 at a first end of the fluid flow path952 configured to couple to the outlet connection 105, a fluid outlet956 at a second end of the fluid flow path 952, a valve seat 970, and aconnector 980 that engages the valve seat 970 to prevent fluid flowbetween the fluid inlet 954 and the fluid outlet 956 via the fluid flowpath 952. The connector 980 is configured to move relative to the valveseat 970 in response to a threshold pressure within the fluid flow path952 to allow fluid flow between the fluid inlet 954 and the fluid outlet956 of the priming valve 950 via the fluid flow path 952. In someimplementations, the threshold pressure can be 5-50 psi. For example,the connector 980 may be configured to remain engaged with the valveseat 970 until a pressure of 50 psi is present in the fluid flow path952 that causes the connector 980 to move relative to the valve seat970.

The valve seat 970 includes a sidewall 972 extending between an inletend 972 a and an outlet end 972 b of the valve seat 970. The connector980 includes a sidewall 982 extending between an inlet end 982 a and anoutlet end 982 b of the connector 980. In some implementations, thesidewalls 972, 982 can be cylindrical sidewalls forming a cylindricallyshaped valve seat 970 and a cylindrically shaped connector 980. At leasta portion of the valve seat 970 extends within the connector 980, e.g.,coaxially within the connector 980 as shown in FIGS. 8 and 9 , such thatan inner surface 983 a of the sidewall 982 of the connector 980 faces anouter surface 973 b of the sidewall 972 of the valve seat 970.

The outer surface 973 b of the sidewall 972 of the valve seat 970comprises a lip portion 974 that extends radially outward from thesidewall 972 of the valve seat 970. For example, a diameter of the valveseat 970 at the lip portion 974 is greater than a diameter of theremainder of the valve seat 970. The inner surface 983 a of the sidewall982 of the connector 980 is slidingly and sealingly engaged with the lipportion 974 of the valve seat 970. For example, the lip portion 974 ofthe valve seat 970 may include a molded lip seal, e.g., as shown in FIG.10 , or an o-ring configured to form a fluid tight seal with the innersurface 983 a of the sidewall 982 of the connector 980 while stillenabling the sidewall 982 of the connector 980 to slide along the lipportion 974.

An inner surface 973 a of the sidewall 972 of the valve seat 970 definesa first portion of the fluid flow path 952 extending from the fluidinlet 954 of the priming valve 950 to at least one opening 990 in thesidewall 972 of the valve seat 970. The at least one opening 990 in thesidewall 972 of the valve seat 970 is located in a direction toward thefluid outlet 956 of the priming valve 950 with respect to the lipportion 974 of the valve seat 970. For example, as shown in FIGS. 8 and9 , two openings 990 are located on opposite sides of the sidewall 972and to the right of the lip portion 974 towards the fluid outlet 956.Evenly spaced openings, such as the two openings 990 shown in FIGS. 8and 9 enable the pressure in the fluid flow path to be more evenlydistributed within the priming valve 970 and on the connector 980. Theinner surface 983 a of the sidewall 982 of the connector 980 and theouter surface 973 b of the sidewall 972 of the valve seat 970 define asecond portion of the fluid flow path 952 extending from the opening(s)990 toward the fluid outlet 956 of the priming valve 950.

The connector 980 is configured to move axially away from the inlet end972 a of the valve seat 970 in a direction toward the outlet end 972 bof the valve seat 970 in response to the threshold pressure within thefluid flow path 952 to allow the fluid to flow between the fluid inlet954 and the fluid outlet 956 of the valve 950 via the fluid flow path952.

In some examples, a portion of the sidewall 982 of the connector 980 canextend radially inward at the inlet end 982 a of the connector 980. Forexample, as shown in FIGS. 8 and 9 , retainer 984 can extend radiallyinward at the inlet end 982 a of the connector 980. The retainer 984extends radially inward farther than the lip portion 974 extendsradially outward. The outer surface 973 b of the sidewall 972 of thevalve seat 970 comprises at least one abutment surface 976 that extendsradially outward from the sidewall 972 of the valve seat 970. Forexample, a height of the lip portion 974 facing toward the fluid inlet954 of the priming valve 950 can form the at least one abutment surface976. The at least one abutment surface 976 is configured to engage theretainer 984 to inhibit further movement of the connector 980 axiallyaway from the inlet end 972 a of the valve seat 970 in the directiontoward the outlet end 972 b of the valve seat 970. For example, theconnector 980 is enabled to move relative to the valve seat 970 asufficient distance to open the fluid flow path 952 at the fluid outlet956 of the priming valve 950 to a desired or predetermined width, (e.g.,to achieve a desired flow rate based on the threshold pressure in thefluid flow path 952 and/or a flow rate and volume of a fluiddelivered/to be delivered via the fluid flow path 952), after which theconnector 980 is prevented from any further movement in that directionby the retainer 984 engaging the at least one abutment surface 956. Theretainer 984 may be formed by applying heat and/or ultrasonic waves tothe sidewall 982 of the connector 980 to extend the sidewall 982radially inward.

In another example, as shown in FIG. 11 , the inner surface 983 a of thesidewall 982 of the connector 980 can include at least one detent 986extending radially inward from the sidewall 982. The at least one detent986 may be located at any position along the sidewall 982 between theinlet end 982 a of the sidewall 982 and the lip portion 974 of the valveseat 970 when the priming valve 950 is in the closed position. The atleast one abutment surface 976 is configured to engage the at least onedetent 986 to inhibit further movement of the connector axially awayfrom the inlet end 972 a of the valve seat 970 in the direction towardthe outlet end 972 b of the valve seat 970. A location of the at leastone detent 986 may be selected to enable the connector 980 to moverelative to the valve seat 970 a sufficient distance to open the fluidflow path 952 at the fluid outlet 956 of the priming valve 950 to adesired or predetermined width, (e.g., to achieve a desired flow ratebased on the threshold pressure in the fluid flow path 952 and/or a flowrate and volume of a fluid delivered/to be delivered via the fluid flowpath 952), after which the connector 980 is prevented from any furthermovement in that direction by the at least one detent 986 engaging theat least one abutment surface 956.

In one implementation, the outer surface 973 b of the sidewall 972 ofthe valve seat 970 may include at least one additional abutment surface978 extending radially outward from the sidewall 972. The at least oneadditional abutment surface 978 is located in a direction toward theinlet end 972 a of the valve seat 970 with respect to the at least oneabutment surface 976. The at least one additional abutment surface 978is configured to engage the at least one detent 986 to inhibit movementof the connector 980 axially toward the inlet end 972 a of the valveseat 970 in a direction away from the outlet end 972 a of the valve seat970. The at least one detent 986 and the additional abutment surface 978may be configured such that when a predetermined pressure or thethreshold pressure is applied to the fluid flow path 952 the at leastone detent can overcome the additional abutment surface 978, e.g.,through deformation of the additional abutment surface 978, the detent986, and/or the sidewall 982 of the connector 980, enabling furthermovement of the connector 980 axially away from the inlet end 972 a ofthe valve seat 970 in the direction toward the outlet end 972 b of thevalve seat 970. After overcoming the additional abutment surface 978,engagement of an opposite face of the additional abutment surface 978with the at least one detent 976 can act to inhibit the connector 980from returning to the closed position by inhibiting movement of theconnector axially toward the inlet end 972 a of the valve seat 970 inthe direction away from the outlet end 972 b of the valve seat 970. Itis noted that it can be beneficial to form the connector 980 as twoseparate pieces, e.g., as shown in FIG. 11 , if detents 986 are includedto retain the valve seat 970, with the two separate pieces being weldedtogether after the valve seat 970 is assembled onto the inlet end 982 a(left half in FIG. 11 ) of the connector.

In some examples, the priming valve 950 may include an additional fluidflow path 992 between the fluid inlet 954 and the fluid outlet 956 ofthe priming valve 950. The additional fluid flow path 992 can be sizedand shaped to provide a visual indication of mist formation and/or tocontrol back pressure within the fluid flow path 952. In someimplementations, the additional fluid flow path 992 may be a needlehaving an inner diameter sufficiently small to be capable of generatingback pressure in the flow sensor 210 when fluid is delivered from thesyringe 900. For example, the additional fluid flow path 992 may be aneedle having an outlet of approximately 30 G (0.16 mm ID). In otherexamples, the additional fluid flow path 992 may have an inner diameterof 0.1-0.2 mm. The priming fluid delivered from the syringe 900 buildsback pressure within the flow sensor 210. In some examples, theincreased fluid pressure of 5-50 psi within the flow sensor 210 can bemaintained for a predetermined period of time. For example, thepredetermined period of time may be approximately 1-60 seconds.

The inner surface 983 a of the sidewall 982 of the connector 980 caninclude an angled surface 987 that extends radially inward toward theoutlet end 982 b of the connector 980 and beyond the outlet end 972 b ofthe valve seat 970. The outer surface 973 b of the sidewall 972 of thevalve seat 970 includes a valve seat surface 977, and the angled surface987 of the connector 980 can engage the valve seat surface 977 of thevalve seat 970 to prevent fluid flow between the fluid inlet 954 and thefluid outlet 956 via the fluid flow path 952. The priming valve 950 mayinclude a valve outlet connection 999 at the fluid outlet 954 at thesecond end of the fluid flow path 952 configured to connect to an inletconfigured to deliver the fluid from the administrable fluid source to afluid pathway that provides the fluid to a medical device. For example,the valve outlet connection 999 may be a Luer-Lok connection or LuerSlip connection.

Method of Readying a Flow Sensor System with a Relief Valve

The priming valve 950 can be used instead of the cap 910 or the ventedcap 940 in use of a flow sensor system 200 of the present disclosure asdescribed herein in the section titled “Method of Readying a FlowSensor”, accordingly its use therein is described only briefly below.For example, while the flow sensor 210 is pressurized by the fluid fromthe syringe 900, at least one first signal is generated by the flowsensor 210 to characterize at least one attribute of fluid. In variousexamples, the at least one attribute may be fluid flow rate and/or fluidpressure. The manual increase of fluid pressure within the flow sensor210, while keeping the outlet connection 105 capped, helps eliminate anyair between the interior surface of the flow path of the flow sensor 210and the fluid. In this manner, the interior surface of the flow path ofthe flow sensor 210 is fully wetted to allow for an increased ultrasonicsignal transmission of the flow sensor 210.

When the fluid pressure within the flow sensor 210 reaches the thresholdpressure of the priming valve 950, which until this point has beenclosed to prevent fluid flow from the outlet connection 105, the primingvalve opens to allow the flow of the fluid from the outlet connection105. The priming valve is formed and configured such that the thresholdpressure results in the interior surface of the flow path of the flowsensor 210 being fully wetted to allow for an increased ultrasonicsignal transmission of the flow sensor 210 before the priming valve 950opens to release the pressure. In some examples, the increased fluidpressure of 5-50 psi within the flow sensor 210 can be maintained for apredetermined period of time before the threshold pressure is reached.For example, the predetermined period of time may be approximately 1-60seconds. The opening of the priming valve 950 can provide an indicationto a medical practitioner that sufficient pressure within the flowsensor 210 has been achieved to ensure that the flow sensor 210 is fullywetted.

Next, the pressure on the plunger 920 of the syringe 900 can be releasedand the valve outlet connection 999 is attached to an inlet of a fluidpathway (not shown) configured for delivering fluid from anadministrable fluid source, such as the syringe 900, to a patient.Alternatively, after the pressure on the plunger 920 of the syringe 900is be released, and the priming valve 950 can be removed from the Luertip 109, and the outlet connection 105 is attached to an inlet of afluid pathway (not shown) configured for delivering fluid from anadministrable fluid source, such as the syringe 900, to a patient. Insome examples, the fluid pathway may be a catheter configured forconnecting to a patient. Prior to connecting the fluid pathway to thepatient, fluid from the syringe 900 is first expelled from the fluidpathway, such as during the priming of the fluid pathway, which can beperformed with the priming valve still attached to the outlet connection105, thereby providing an additional ease of use for medicalpractitioners. As the fluid is delivered from the syringe 900, the fluidflows through the flow sensor 210 and out of the fluid pathway. In someexamples, 2-7 ml of fluid may be delivered from the syringe 900 throughthe fluid pathway. The flow sensor 210 may generate at least one secondsignal of the same type as the first signal in order to characterize atleast one attribute of the fluid. For example, the second signal maycharacterize the pressure and/or flow rate of fluid through the flowsensor 210. In some examples, the second signal may be increased (i.e.,have higher strength) than the first signal due to the internal surfacesof the flow path of the flow sensor 210 being fully wetted. For example,the second signal may be increased over the first signal by 120%, 160%,or 180%, inclusive of the values therebetween. The flow sensor 210 isnow primed and ready for use in a fluid delivery procedure.

Method of Using the Flow Sensor System

To use a primed flow sensor system 200, a user attaches the flow sensor210 to the base 220 by joining the flow sensor 210 (tubing side) andbase 220 front sections first, and then snapping the two together.Preferably, an audible snapping sound is heard to indicate a secureconnection between the flow sensor 210 and the base 220. In one example,connecting the flow sensor 210 to the base 220 automatically powers onthe flow sensor system 200. In one example, the connection of the flowsensor 210 to the base 220 is verified by a blinking light on the base220. In other examples, other indicators may be used.

The flow sensor system 200 is now ready for delivery of IV medications.In one example, in the event of a flow sensor system 200 failure(excluding the IV fluid pathway), the flow sensor system 200 will stillallow standard medication or fluid delivery through the port.

Next, giving an injection using the flow sensor system 200 will bediscussed. First, the injection port 130 is cleaned by swabbing the hubaccording to normal hospital procedure. Next, a syringe 900 can beattached to the injection port 130 of the flow sensor 210 by completelyrotating the syringe 900 until the syringe 900 stops, i.e., a secureconnection between the syringe 800 and the injection port 130 is made.Ideally, the caregiver double checks each medication name andconcentration on the syringe 900 prior to attachment to the injectionport 130 to assure the correct medication is given.

The flow sensor 210 can be disposed after the flow sensor 210 is used tosense the flow of at least one fluidic medicament. The flow sensor base220 can be used with a plurality of different flow sensors 210.

While this disclosure has been described as having exemplary designs,the present disclosure can be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the disclosure using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as they become within known orcustomary practice in the art to which this disclosure pertains andwhich fall within the limits of the appended claims.

What is claimed is:
 1. A priming valve, comprising: a valve comprising afluid flow path, a fluid inlet at a first end of the fluid flow path, afluid outlet at a second end of the fluid flow path, a valve seatincluding an inlet end at the first end of the fluid flow path and anoutlet end at the second end of the fluid flow path, and a connectorconfigured to move relative to the valve seat, wherein the connector isconfigured to move axially away from the inlet end of the valve seat ina direction toward the outlet end of the valve seat in response to athreshold pressure within the fluid flow path to allow the fluid to flowbetween the fluid inlet and the fluid outlet of the valve.
 2. Thepriming valve of claim 1, wherein the threshold pressure is 5-50 psi. 3.The priming valve of claim 1, wherein the connector comprises a sidewallextending between an inlet end and an outlet end of the connector,wherein the valve seat comprises a sidewall extending between an inletend and an outlet end of the valve seat, and wherein at least a portionof the valve seat extends within the connector such that an innersurface of the sidewall of the connector faces an outer surface of thesidewall of the valve seat.
 4. The priming valve of claim 3, wherein theouter surface of the sidewall of the valve seat comprises a lip portionthat extends radially outward from the sidewall of the valve seat, andwherein the inner surface of the sidewall of the connector is slidinglyand sealingly engaged with the lip portion of the valve seat.
 5. Thepriming valve of claim 3, wherein the inner surface of the sidewall ofthe connector comprises an angled surface that extends radially inwardtoward the outlet end of the connector, wherein the outer surface of thesidewall of the valve seat comprises a valve seat surface, and whereinthe angled surface of the connector engages the valve seat surface ofthe valve seat to prevent fluid flow between the fluid inlet and thefluid outlet via the fluid flow path.
 6. The priming valve of claim 4,wherein the lip portion of the valve seat comprises one of a molded lipseal and an o-ring.
 7. The priming valve of claim 4, wherein an innersurface of the sidewall of the valve seat defines a first portion of thefluid flow path extending from the fluid inlet of the valve to at leastone opening in the sidewall of the valve seat, wherein the at least oneopening in the sidewall of the valve seat is located in a directiontoward the fluid outlet of the valve with respect to the lip portion ofthe valve seat, and wherein the inner surface of the sidewall of theconnector and the outer surface of the sidewall of the valve seat definea second portion of the fluid flow path extending from the openingtoward the fluid outlet of the valve.
 8. The priming valve of claim 6,wherein a portion of the sidewall of the connector extends radiallyinward at the inlet end of the connector.
 9. The priming valve of claim8, wherein the outer surface of the sidewall of the valve seat comprisesat least one abutment surface that extends radially outward from thesidewall of the valve seat, wherein the at least one abutment surface isconfigured to engage the portion of the sidewall of the connector thatextends radially inward to inhibit further movement of the connectoraxially away from the inlet end of the valve seat in the directiontoward the outlet end of the valve seat.
 10. The priming valve of claim6, wherein the inner surface of the sidewall of the connector comprisesat least one detent extending radially inward from the sidewall.
 11. Thepriming valve of claim 10, wherein the outer surface of the sidewall ofthe valve seat comprises at least one abutment surface extendingradially outward from the sidewall, wherein the at least one abutmentsurface is configured to engage the at least one detent to inhibitfurther movement of the connector axially away from the inlet end of thevalve seat in the direction toward the outlet end of the valve seat. 12.The priming valve of claim 11, wherein the outer surface of the sidewallof the valve seat comprises at least one additional abutment surfaceextending radially outward from the sidewall, wherein the at least oneadditional abutment surface is located in a direction toward the inletend of the valve seat with respect to the at least one abutment surface,and wherein the at least one additional abutment surface is configuredto engage the at least one detent to inhibit movement of the connectoraxially toward the inlet end of the valve seat in a direction away fromthe outlet end of the valve seat.
 13. The priming valve of claim 1,wherein the valve further comprises an additional fluid flow pathbetween the fluid inlet and the fluid outlet of the valve.
 14. Thepriming valve of claim 1, wherein the valve comprises a connection atthe fluid outlet at the second end of the fluid flow path configured toconnect to an inlet configured to deliver the fluid from anadministrable fluid source to a fluid pathway that provides the fluid toa medical device.
 15. A flow sensor sub-assembly for sensing flow of afluidic medicament comprising: a fluid port comprising: a fluid channel,a fluid inlet at a first end of the fluid channel, and a fluid outlet ata second end of the fluid channel; and a priming valve attached to thefluid outlet at the second end of the fluid channel, wherein the primingvalve is configured to prevent fluid flow from the fluid outlet at thesecond end of the fluid channel when closed, and wherein the primingvalve is configured to open to allow the flow of the fluid from thefluid outlet at the second end of the fluid channel in response to athreshold pressure within the fluid channel, wherein the priming valvefurther comprises an additional fluid flow path between the fluid inletand the fluid outlet of the valve.